Determination of Normal Paraffins and Normal Olefins in Petroleum Distillates

Mass Spectrometric Determination of the Ratio of Branched to Normal Hydrocarbons up to C18 in Fischer-Tropsch Product.

“…Molecular Sieve Technique. Three Molecular Sieve techniques were investigated: Simple mixing of the sample and sieve material (9), the vacuum evaporation method developed by Nelson, Grimes, and Heinrich (10) and an elution technique developed by O'Connor and Norris (11). The elution technique, described completely in (11), gave a better separation of normal and branched components (above Cm) in synthetic mixtures and was therefore used in characterizing the Briefly, the technique is as follow's.…”

“…Some of these factors are discussed by Bailey and Yaffe (1). Under conditions of constant velocity and uniform potential-gradient and where there are no specific interactions of the ion with the paper or background electrolyte (6,10,18), U = (Ua± Uc) (jj2 (1) The factor \ j ) , where l' is the average distance which an ion must travel in the paper to move between points separated by a straightline distance, l, corrects for the increased distance an ion has to travel in the channels of the paper. This factor is a function of the absorbance (the volume of liquid present per gram of paper) (5), and perhaps the type of paper.…”

Direct Determination of Isoparaffins and n-Paraffins in Olefin-Free Gasoline by Mass Spectrometer

“…A satisfactory method for determining the isoparaffin-paraffin ratio in gasoline is of wide interest. Molecular Sieve procedures recently reported by Schwartz and Brasseaux (9) and Nelson, Grimes, and Heinrich (6) appear to measure the re-paraffin content of various hydrocarbon mixtures rapidly and accurately. However, total paraffins must be determined by some other procedure, to measure the isoparaffin concentration.…”

Molecular Sieve Adsorption. Application to Hydrocarbon Type Analysis

“…29, 928 (1957) . (7) Golay, M. J. E., "Gas Chromatography," D. H. Desty, ed., p. 36, Academic Press, New York, 1958. (8) Golay, M. J. E., Nature 182, 1146 (1958) .…”

“…Barrer (I, 2) reported the use of naturally occurring zeolitic minerals for the adsorption of normal paraffins and investigated conditions for adsorption, the size of the molecules adsorbed, and the relative rates of adsorption on chabazite. When synthetic zeolites became available commercially, Nelson, Grimes, and Heinrich (7) methods were rapid and accurate but were limited to narrow boiling fractions. This paper describes a technique which permits an accurate determination of the normal hydrocarbon content of petroleum distillates boiling between 100°and 650°F.…”